The present invention relates to a combustion engine, comprising a housing with a chamber, In which is arranged a rotor which is provided with a number of vanes which extend in radial direction to the wall of the chamber and which divide the chamber into a number of compartments, wherein each of the compartments is intended for performing at least one of the following functions: a) drawing in and/or compressing gas required for the combustion; b) bringing the fuel to combustion; c) producing work; and d) discharging combustion gases, wherein a first pair of vanes is mounted rotatably on a first rotation axis and wherein a second pair of vanes is mounted rotatably on a second rotation axis, which rotation axes are arranged eccentrically in the chamber.
Such an internal combustion engine is known in the field as a rotary engine. The rotary engine has a number of advantages compared to the traditional internal combustion engine, the “Otto engine”. By replacing the piston with a rotor, the rotary engine can in principle suffice with just one chamber. The rotary engine now has an inherently balanced construction, whereby added balance weights, as are usual in the Otto engine, can be omitted. The rotary engine therefore has a minimum of components, which increases the reliability and reduces the production costs.
An example of a rotary engine is described in the American patent specification U.S. Pat. No. 6,070,565. In the known rotary engine the vanes are coupled in pairs by means of a yoke which translates round a fixed point. The translating movement of the vanes in the rotor is not hereby smooth since the vanes briefly come to a standstill each time the movement of the yoke is reversed. This results in friction losses which adversely affect the efficiency of the rotary engine. The jolting movement also generates extra vibrations. The maximum rotation speed is furthermore limited by this construction.
The invention has for its object to provide a rotary engine of the type stated in the preamble with an improved construction and a higher efficiency. The rotary engine according to the invention has the feature for this purpose that the vanes in each pair are independently rotateable relative to each other. The independently rotatable vanes have the advantage of always making a smooth movement at a practically constant angular speed. The rotary engine hereby has low vibration and undergoes relatively low acceleration and deceleration forces, which contributes toward a higher efficiency as well as a greater comfort at a lower weight.
According to a first preferred embodiment of the combustion engine according to the invention, each of the vanes in the first pair (5A, 5B) is provided with a protruding portion for mounting on the rotation axis 5. According to a second preferred embodiment of the combustion engine according to the invention, each of the vanes in the second pair (6A, 6B) is provided with a recess with a protruding portion on either side for mounting on the rotation axis 6. Each protruding portion is preferably provided with a bearing which is mounted round the rotation axis. This results in an extremely stable construction, also at high rotation speeds.